Swing recorder



March 16, 1965 E. J. BETINIS swmc RECORDER 3 Sheets-Sheet l Filed Feb. 1

52 DOW/V 7 JIV/NG M i n: 2% f.

March 16, 1965 E. J. BETINIS 3,173,348

SWING RECORDER Filed Feb. 1, 1963 3 Sheets-Sheet 2 fizz/912 for: flizazzael J 3622713 m a? I w fiwrlzew United States Patent 3,173,343 SWING RECGRDER Emanuel J. lietinis, 3:72 Fair-hank Road, Mverside, ill. Filed Feb. I, 1963, Ser. No. 255,519 a claims. or. 95-13) This invention relates to a swing recorder by which an athlete may be selectively photographed at a selected key position of a swing. The invention is primarily directed for use by an athlete engaged in a sport which requires the athlete to go through a prescribed swing to either strike or throw an object with either one hand or both. The invention is illustrated herein primarily in connection with a swing of a golf club, but with the principle laid out, the apparatus may be adapted to any game in which an athlete must swing his arm from a stance position which would include cricket, horseshoes, baseball, tennis, etc.

In this instance, the inventor is primarily concerned with providing an athlete with a photograph of himself at a selected position. The athlete then can compare his body and arm attitude with the attitude of a skilled player whereby he may compare his motion with that of the skilled player. Because a swing is something which ordinarily happens in a fraction of a second, an athlete may concentrate his practice on a particular portion of his swing which is causing his difiiculty. In golf, for example, inventor finds that there are twelve critical positions in the course of the golf swing. That is, four in the lip-swing, four in the down-swing and four in the follow-through after the ball has been struck. It is apparent that though slow motion pictures may be made of an athlete progressing through a swing, it is desirable to pinpoint attitudes of various portions of the body at key positions of the swing. It is therefore a principal object of this invention to provide an apparatus that will take a photograph of an athlete in a selected position irrespective of whether the athlete is going through that position .a first or a second time such as in the up-swing and down-swing by a golfer.

Another object of the herein-disclosed invention is to control the taking of a picture by breaking a beam of light between a light source and a photoelectric cell by means of the hand of an athlete.

It is a further object of the present invention to provide a means for taking a photograph of an athlete at a key position of his swing so that he may compare his attitude with the attitude of a skilled athlete engaged in a similar swing.

It is a still further object of the instant invention to provide a swing photographer which may be used to photograph athletes of varying height and still photograph the athletes at the same key swing positions, irrespective of the height of the athlete.

Other objects and uses of the herein-disclosed invention will become readily apparent to those skilled in the art upon a perusal of the following specification in light of the accompanying drawings in which:

FIGURE 1 is a perspective view of a golfer standing in front of a frame supporting a plurality of photoelectric cells which constitute a portion of the instant invention and the path of a golf club head as swung by the shown golfer is shown in diagrammatic view;

FIGURE 2 is 'a side elevation of the frame and photo electric cell-s shown in FIGURE 1 along with the light source box and a camera;

FIGURE 3 is an electrical circuit diagram of the electrical circuit used to trigger selectively the camera;

FIGURE 4 is an electricalcircuit diagram of a portion of thecircuit diagram shown in FIGURE 3, but showing only the parts of the circuit which are active in a downswing or a second energization of one of the photoelectric cells; and

3,173,348 Patented Mar. 16, 1965 FIGURE 5 is an electrical circuit diagram of a portion of the circuit diagram shown in FIGURE 3, but showing only the parts of the circuit which are active when the camera is to be actuated by the first energization of one of the photoelectric cells.

Referring now to the drawings and especially to FIG- URES 1 and 2, a swing recorder embodying the instant invention consists of three principal portions, that is, a photographing means 10, a control frame 12 in the photographing field of the photographing means 10, and a cabinet 14 which connects the photographic means with the control frame to selectively trigger the photographic means.

In this instant, the photographic means is conventional in that it includes a camera 16 which is of the general type adapted to receive film which may be developed in the camera for prompt development of the film and immediate printing of the picture. A suitable light source 18 is attached to the camera through a conventional 'synchro nizing device in order to provide light at the same time that the camera has its shutter opened for taking a picture. The camera with the light is mounted on a conventional tripod 20 to support the camera at an appropriate height. In this instance, the camera is operated by a cable 22 which is connected to the cabinet 14 in a manner which will be described hereinafter. Although a mechanical cable release is shcwn in this instance, it is readily apparent that a solenoid may be mounted on the camera to trigger a shutter control on the camera, and thus, it would be necessary only to provide electrical wires to the camera.

As was mentioned above, a control frame is positioned in the photographic field of camera 16. The control frame includes a support frame 24 having brackets 26 attached thereto for holding the frame in an upright position. The support frame has a plurality of braces 27 formed in a grid pattern as shown in FIGURE 1. These braces 27 perform a dual function in that they provide a reference grid in a photograph and they support a mounting ring 28 which mounting ring has a plurality of photoelectric cells fixed thereto. There are eight photoelectric cells mounted on the support frame, six of which are, in this instance, mounted on the support ring. A first photoelectric cell 33 is mounted in the lowermost portion of the ring. A second photoelectric cell 32 is mounted in a first quadrant of the support ring. A third photoelectric cell 34 is mounted in a position between the first and the second quadrant of the ring. A fourth photoelectric cell 36 is mounted in the second quadrant of the ring; and a fifth photoelectric cell 38 is mounted in the uppermost portion of the frame and above the second quadrant of the ring. Three additional photoelectric cells are mounted on the remainder of the frame. A sixth photoelectric cell 46 is mounted in the third quadrant of the ring, whereas a seventh photoelectric cell 42 is mounted opposite the third photoelectric cell 34. An eighth photoelectric cell 44 is mounted on the same level as the fifth photoelectric cell, but above the fourth quadrant of the ring.

A plurality of switches are also mounted on the support frame 12. A master control switch 46 is positioned adjacent to the second photoelectric cell 32. The master control switch is operated by a coin control device 4? which is conventional in construction and so connected to the switch :5 that an appropriate value of coins must first be deposited to close the switch. An up-down control switch 4d is positioned adjacent to a sixth photo electric cell iii. A selector switch 50 is positioned in the center of the support ring 28. The photoelectric cells are connected to the cabinet 14 by means of an electrical cable 52. Cable 52 has a ready switch 54 in series with it for reasons which will become apparent hereinafter. The photoelectric cells mentioned above are conventional in their operation, and therefore, there is a plurality of light sources 56 mounted in the cabinet I l. There are eight light sources and each light source is directed to its respective photoelectric cell in order to energize the cell. In this instance, each of the light sources is an infrared light for reasons which will also become apparent hereinafter, though it may be noted that an infrared light does not appear particularly bright to one viewing it. It should also be noted that the light sources 56 are clustered together and are positioned well below a line extending through the center of the support ring 26 and perpendicular to said ring, so that a truncated cone is defined by straight lines extending between each of the photoelectric cells and its respective light source.

Looking now to FIGURE 3, a circuit diagram of the instant invention is shown therein. The light sources 56 are shown as a block and are shown as being connected to an electrical power source. The electrical power source is any conventional source of power which in this instance is a source of 110 volt 60 cycle, alternating current. The power source is connected to an amplifier 53 which is physically located in cabinet 14. The amplifier 58 is a conventional amplifier. Between the power source and the amplifier, there is connected in series the master switch 46 and the ready switch 54. The photoelectric cells 30, 32, 34, 36, 38, 40, 42; and 44 are represented in circuit diagram 3 and subse uent circuit diagrams by a block labelled photoelectric cells though it is apparent that each cell has its own connection to the amplifier. The selector switch 50 is connected to the photoelectric cells and to the amplifier 58, so that, a given photoelectric cell is connected to the amplifier while the remainder of the cells have no effect on the circuit. A first normally open relay so is connected to the amplifier. The relay till is in turn connected to a stepping relay 62.

The relay 6%) includes a coil 64 having a movable contact 65 cooperative therewith which coil is connected to a movable contact 66 of up-down switch 48. The switch 48 is a double-pole double-throw switch to determine whether the camera will be activated on a first or second interruption of a light beam to a cell. When contact 66 is in engagement with a pole 68 of the switch, coil 64 is connected to a coil '76 of stepping relay 62. It may be noted that when contact 66 is in its other position, that is, in contact with a pole 72, the coil 64 is then connected to the amplifier to complete the circuit. One side of the relay so is connected to a battery 74 which is connected to a solenoid which constitutes a load 76. The solenoid operates the cable 22 to operate the shutter mechanism of camera 16 and to actuate the light source 18. The same side of the relay is also connected to a movable contact '78 of the stepping relay 6?...

In this instance, the stepping relay 62 is one which has 10 poles, indicated as poles, A, B, C, D, E, F, G, H, I and I, consecutively. It may be noted that poles A, C, E, G and I are electrically inter-connected, whereas the remaining poles B, D, E, H and I are not connected to anything. The stepping relay is in turn connected to a second normally open relay 8t It may be seen in FIGURE 3 that relay 8t has a coil 82 connected in series with coil 7d and the coil 82 is connected to the amplifier. The relay 8ft has a fixed contact 83 connected to the poles A, C, E, G and I and a movable contact 8 connected to the load 76, which movable contact 84 is engageable with contact 83. Engagement of contact 84 with contact 83 electrically connects relay 62 with a line 35.

The load 76 is connected to a contact 86 by means of line 35, which contact 8%? is engageable with a movable contact 33 of switch 4-8. As is evident in FIGURE 3, contacts 66 and 88 are inter-connected. The contact 88 is connected to the amplifier so that when contact all is in engagement with contact 86, the load is connected to the amplifier.

In order that an athlete have his photograph taken during a specified portion of a swing, it is only necessary for the attdete to position himself between the support ring 28 and the camera 16. In this instance, a golfer is used as an example. It should be noted that though a golfer is used in the example, the present device may be adapted for other sports such as tennis, baseball, horseshoes, etc. It may be appreciated that in view of the fact golfers have varying height and arm length, it is necessary to provide a device which may accommodate a golfer of any height by arranging the photoelectric cells in a closed figure with the fifth and eighth cells at a substantial height over the ground, and the light sources near the ground. The distance that the golfer is positioned from the support ring determines the height of the uppermost light beam. Furthermore, the third and seventh photoelectric cells are at the outermost portion of the circle and the effective light beams are brought in closer for the shorter golfer who has shorter arms than the tall golfer. Thus, the truncated conical surface determined by the light beams provides for automatic adjustment for varying heights simply by the positioning of the golfer a selected distance from the support bar. Appropriate marking indicia may be placed on the ground to indicate where golfers of various heights are to stand.

In using the instant device, the golfer must select which portion of his swing is to be photographed. As is well known, a golf swing may be divided into three parts. First the player addresses the ball in the attitude substantially as shown in phantom view in FIGURE 1. From the address position the club head is retracted in a swing which is known as the tip-swing. As the club head is retracted in the upswing in the path shown in dotted form, the golfer shifts his weight from both feet to substantially one foot, and as he brings his club back in the tip-swing he cocks his wrists. He brings the club to the top of his tip-swing, hesitates for a moment, and then commences his down-swing, shifting his weight from one foot to the other and uncocking his Wrists immediately before striking the ball with the club. After striking the ball, the golfer goes into the follow-through position of his swing. His arms are extended, and there is a pivoting action by his body during the follow-through, so that the path of the golf head is subtantially an ellipse in a tilted plane as shown in FIGURE 1. The instant device allows a golfer to take a photograph of his swing at any one of eight critical positions. It may be appreciated that more positions may be added, but it appears that eight is sulficient.

In order to take a photograph, it is necessary that the master switch 46 be closed by depositing an appropriate value of coins as was mentioned above. The golfer then selects whether he wishes to take a photograph in the tip-swing, the down-swing or the follow through. In the event that he wishes to take the photograph in either the up-swing or the follow through, he sets the tip-down switch 48 in the up position so that contacts 68 and 88 are in the attitude as shown in FIGURE 5. He also adjusts the selector switch S ll to energize a proper photoelectric cell so that his swing will be photographed in the position which he desires. With the master switch 56 closed, the up-down switch 48 in the proper attitude, and the selector switch 50 properly positioned, he then may assume his stance as addressing the ball. It may be appreciated that he may have interrupted the light beam from the light source to the selected photoelectric cell during the time that he assumes his proper stance. In order that the device be triggered only when desired, there is provided the ready switch 54. When the golfer is in his proper stance, he then closes ready switch 54 so that the entire circuit is ready for operation.

When the golfers hands interrupt the light beam from the light source to the photoelectric cell, a pulse is generated which is amplified by amplifier 58. The amplifier 5S energizes coil 6 which closes contact 65 of relay 69 and there is an impulse.

A before the relay 6t closes.

62 and 89, respectively.

It may be noted that current flows through the coil 64 to contact 66 of switch 48 which is in engagement with contact 72 to connect the coil with the amplifier. When the contact 64 is closed, a pulse is delivered to the batteries 74 through the solenoid of load 76 which is connected back through the contact 88 which is in cont act with contact 86. The solenoid operates the shutter mechanism of camera 16 as well as the light source 13 to take a photograph of the golfer at a selected attitude. It should be noted that the response time of the photoelectric cell is 500 microseconds so that there is a very short time lapse between the breaking of the light beam and the taking of the photograph.

In order to take a photograph when the golfer is going through a down-swing, it is necessary to change the position of the up-down switch 48, so that it is in the attitude as shown in FIGURES 3 and 4. FIGURE 4 shows the portion of the circuit which is operable in the downswing. When the golfer wishes to take a photograph of his swing in the down-swing, he of course adjusts the selector switch 50 to energize an appropriate photoelectric cell such as the third photoelectric cell 34. The master switch 46 and the ready switch 54 are closed to energize the entire circuit. It is readily apparent that when the golfer brings back his arms in the up-swing or backswing the light source to the photoelectric cell 34 is broken This impulse is amplified by amplifier 58 and a pulse is passed on to the coil 64 of relay 60. The pulse also passes through contact 66 to coil 70 of the step relay 62. It should be noted that as the coil starts to move contact 65 into a closed position, the coil 70 moves the contact 78 from post A to open the circuit so that even though there is a pulse to coil 82 which closes contact 84 of relay 80, the circuit from the load is open even though relay 60 is closed. It is important that the stepping relay disengage the active post By the time the relay 60 closes, the contact 78 of relay 62 is in contact with post B which is a dead post, so that there is no current to the load through this portion of the circuit.

The second pulse operates the camera. When the golfer goes into his down-swing, he again interrupts the light beam to the photoelectric cell thereby causing a second pulse which is amplified by the amplifier. This second pulse energizes coils 64, '70 and 82 of relays 60, When the relay 6% closes, the contact '78 comes in contact with post C which is connected to the relay 8% which is also closed, thus providing a complete circuit to the solenoid in the load to operate the shutter as well as the light source.

any errors which he may make. Furthermore, it may be appreciated that he may compare his photograph with the photograph of a similar size professional golfer who has a substantially perfect swing. The grid on the support also gives the golfer a frame of reference for his attitude at a given time so that a comparison may be made more accurately.

Although the embodiment shown and described herein is for use with a golfer, it is readily apparent that additional positions may be added, and there may be a rearrangement of parts in order to accommodate athletes engaged in other sports, such as tennis, horseshoes, baseball, etc. It is of course readily apparent that those skilled in the art may make various modifications and changes in the present device without departing from the 6 spirit and scope of this instant invention. It is to be expressly understood that the present invention is limited only by the appended claims.

What is claimed is:

ll. A swing recorder for photographing an athlete at a selected portion of a swing comprising, in combination, a plurality of photoelectric cells defining a substantially closed figure, a plurality of light sources equal in number to the number of photoelectric cells spaced from the photoelectric cells, each of said light sources being cooperative with a respective photoelectric cell by emitting a beam of light toward its respective photoelectric cell to energize the photoelectric cell, a camera spaced from the photoelectric cells and having a portion of the beam of light from each of the light sources to the respective photoelectric cells in its picture field, a selector connected to the photoelectric cells, a normally open relay connected to the selector to be closed by interruption of a beam of light to a photoelectric cell connected to the relay through the selector, means connected to the relay for operating the camera, a stepping relay connected to said first relay through a switch, said stepping relay having alternate positions connected to a third relay and to said means, said means being connected to the third relay through a second switch, whereby the stepping relay may be selectively connected to the means for operating the camera through the first and second switch to allow a selected photoelectric cell to operate the camera on its second impulse rather than its first thereby allowing an athlete to go through a back swing and photograph a portion of a down swing after the back swing has been completed.

2. A swing recorder for photographing an athlete at a selected portion of a swing comprising, in combination, a

plurality of photoelectric cells defining a substantially closed figure, a plurality of light sources equal in number to the number of photoelectric cells spaced from the photoelectric cells, each of said light sources having a lesser distance to adjacent light sources than the distance between respective adjacent photoelectric cells, each of said light sources being cooperative with a respective photoelectric cell by emitting a beam of light towards its respective photoelectric cell to energize the photoelectric cell, a camera positioned adjacent to the light sources and having the photoelectric cells in its photographic field, a selector connected to the photoelectric cells, a normally open relay connected to the selector and adapted to be closed by interruption of a beam of light to one of the photoelectric cells connected to the relay through the selector, means connected to the relay for operating the camera, a stepping relay connected to the first relay through a switch, said stepping relay having alternate positions connected to a third relay and to said means, said means being connected to the third relay through a second switch, whereby the stepping relay may be selectively connected to the means for operating the camera through the first and second switch to allow a selected photoelectric cell to operate the camera on its second impulse rather than its first impulse .thereby allowing an athlete to go through a back-swing and then photographing a portion of a down-swing after the back-swing has been completed.

3. A swing recorder for photographing an athlete at a selected portion of a swing comprising, in combination, a camera, means connected to said camera for operating the camera, a normally open relay connected to the means for operating the camera for controlling the said means, a stepping relay connected to the relay through a switch, said stepping relay having alternate positions connected to a third relay, said means being connected to the third relay through a second switch, a selector connected to the first'mentioned relay, a plurality of photoelectric cells being connected to the selector and being positioned in the photographic field of the camera, a frame supporting said photoelectric cells in substantially one plane, an identifying grid mounted on said frame adjacent to said photoelectric cells to provide a frame of reference in a photograph, and a plurality of light sources equal in number to the number of photoelectric cells spaced from said photoelectric cells and being positioned adjacent to the camera, each of said photoelectric cells having a greater distance to adjacent photoelectric cells than the distance between respective adjacent light sources, each of said light sources being cooperative with a respective photoelectric cell and determining a straight line between each light source and its respective photoelectric cell, whereby a selected photoelectric cell is connected to the means through the selector, an athlete is positioned before the camera so that a motion by the athlete interrupts a selected light beam to a selected photoelectric cell, and the camera is operated on the second interruption of the light source rather than the first interruption, thereby allowing the athlete to go through a back-swing without a photograph being taken and a portion of a down-swing is taken after the backswing has been completed.

4. A swing recorder for photographing an athlete at a selected portion of a swing comprising, in combination, a plurality of light sources, a plurality of photoelectric cells spaced from said light sources and bein equal in number to the number of light sources, each of said light sources being cooperative with a respective photoelectric cell and determining a straight line between each light source in its respective photoelectric cell, each of said photoelectric cells having a greater distance to adjacent photoelectric cells than a distance between respective adjacent light sources, a camera positioned adjacent to the light sources, means connected to said camera for operating the camera to take a photograph, an electrical power source connected to said means, a normally open relay connected to said means and the electric power source, a stepping relay connected to said relay through a switch, said stepping relay having alternate positions connected to a third relay, said means being connected to the third relay through a second switch, a selector electrically connected to the photoelectric cells and the first-mentioned normally open relay for selectively connecting the photoelectric cells with the relay,

whereby the stepping relay may be selectively connected z to the means for operating the camera through the first and second switches to allow a selected photoelectric cell to operate the camera on its second interruption of light rather than its first interruption, thereby allowing an athlete to go through a back-swing and thus a photograph is taken of a portion of a down-swing after the back-swing has been completed.

5. A swing analyzer for photographing an athlete at a selected portion of a swing comprising, in combination,

a substantially upright frame, a plurality of photoelectric cells mounted on said frame, in substantially one plane, an identifying grid mounted on said frame adjacent to said photoelectric cells to provide a frame of reference in a photograph, a plurality of infrared light sources equal in number to the number of photoelectric cells being spaced from said photoelectric cells, each of said light sources having a lesser distance to adjacent light sources than the distance between respective adjacent photoelectric cells, each of said light sources being cooperative with a respective photoelectric cell, a camera positioned adjacent to the light sources and having the identifying grid and photoelectric cells in its photographic field, a selector connected to the photoelectric cells, a normally open relay connected to the selector for connection with a selected photoelectric cell and to be closed by interruption of a beam of light to a selected photoelectric cell connected to the relay through the selector, means connected to the relay for operating the camera, and a stepping relay connected to the first-mentioned normally open relay through a switch, said stepping relay having alternate positions connected to a third relay, said means being connected to the third relay through a second switch, whereby the stepping relay may be selectively connected to the means for operating the camera through the first and second switch to allow a selected photoelectric cell to operate the camera on its second interruption of light rather than its first interruption of light thereby allowing an athlete to go through a back-swing and thus photograph a portion of a down-swing after the back-swing has been completed.

6. A swing recorder for photographing an athlete at a selected portion of a swing comprising, in combination, a camera, means connected to said camera for operating the camera to take a photograph, an electric power source connected to said means, a normally open relay connected to said means and the electrical power source, a stepping relay connected to the relay through a switch, said stepping relay having alternate positions connected to a third relay, said means being connected to the third relay through a second switch, a plurality of photoelectric cells spaced from the camera and being positioned in the photographic field of said camera, a selector electrically connccted to the photoelectric cells and the first-mentioned normally open relay for selectively connecting a photoelectric cell with the first-mentioned normally open relay, a frame supporting said photoelectric cells, an identifying grid mounted on said frame and positioned adjacent to the photoelectric cells to provide a frame of reference in a photograph, and a plurality of infrared light sources spaced from said photoelectric cells and positioned adjacent to the camera and being equal in number to the number of photoelectric cells, each of said light sources having a lesser distance to adjacent light sources than the distance between respective adjacent photoelectric cells, each of said light sources being cooperative with a respective photoelectric cell and determining a straight line between each light source and its respective photoelectric cell, whereby a selected photoelectric cell is connected to the normally open relay through the selector and the stepping relay may be selectively connected to the means for operating the camera through the first and second switches to allow the selected photocell to operate the camera on its second interruption of light rather than its first interruption, thereby allowing an athlete to go through a backswing and then a photograph is taken of a portion of a down-swing after the back-swing has been completed.

References Cited by the Examiner UNITED STATES PATENTS 212,865 3/ 79 Muybridge 95-1 2,223,849 12/40 Fogler 88-l6 2,825,569 3/58 Alvarez 273186 3,016,812 1/62 Chatlain 95l1 3,116,660 1/64 Goss 346107 X NORTON ANSHER, Primary Examiner.

JOHN M. HORAN, Examiner. 

1. A SWING RECORDER FOR PHOTOGRAPHING AN ATHLETE AT A SELECTED PORTION OF A SWING COMPRISING, IN COMBINATION, A PLURALITY OF PHOTOELECTRIC CELLS DEFINING A SUBSTANTIALLY CLOSED FIGURE, A PLURALITY OF LIGHT SOURCES EQUAL IN NUMBER TO THE NUMBER OF PHOTOELECTRIC CELLS SPACED FROM THE PHOTOELECTRIC CELLS, EACH OF SAID LIGHT SOURCES BEING COOPERATIVE WITH A RESPECTIVE PHOTOELECTRIC CELL BY EMITTING A BEAM OF LIGHT TOWARD ITS REPECTIVE PHOTOELECTRIC CELL TO ENERGIZE THE PHOTOELECTRIC CELL, A CAMERA SPACED FROM THE PHOTOELECTRIC CELLS AND HAVING A PORTION OF THE BEAM OF LIGHT FROM EACH OF THE LIGHT SOURCES TO THE RESPECTIVE PHOTOELECTRIC CELLS IN ITS PICTURE FIELD, A SELECTOR CONNECTED TO THE PHOTOELECTRIC CELLS, A NORMALLY OPEN RELAY CONNECTED TO THE SELECTOR TO BE CLOSED BY INTERRUPTION OF A BEAM OF LIGHT TO A PHOTOELECRIC CELL CONNECTED TO THE RELAY THROUGH THE SELECTOR, MEANS CONNECTED TO RELAY FOR OPERATING THE CAMERS, A STEPPING RELAY CONNECTED TO SAID FIRST RELAY THROUGH A SWITCH SAID STEPPING RELAY HAVING ALTERNATE POSITIONS CONNECTED TO THE THIRD RELAY AND TO SAID MEANS, SAID MEANS BEING CONNECTED TO THE THIRD RELAY THROUGH A SECOND SWITCH, WHEREBY THE STEPPING RELAY MAY BE SELECTIVELY CONNECTED TO THE MEANS FOR OPERATING THE CAMERA THROUGH THE FIRST AND SECOND SWITCH TO ALLOW A SELECTED PHOTOELECTRIC CELL TO OPERATE THE CAMERA ON ITS SECOND IMPULSE RATHER THAN IS FIRST THEREBY ALLOWING AN ATHLETE TO GO THROUGH A BACK SWING AND PHOTOGRAPH A PORTION OF A DOWN SWING AFTER THE BACK SWING HAS BEEN COMPLETED. 